Abstract
We present the first triple-axis neutron scattering measurements of magnetic fluctuations in nanoparticles using an antiferromagnetic reflection. Both the superparamagnetic relaxation and precession modes in hematite particles are observed. The results have been consistently analyzed on the basis of a simple model with uniaxial anisotropy and the Néel-Brown theory for the relaxation.
- Received 1 July 1997
DOI:https://doi.org/10.1103/PhysRevLett.79.4910
©1997 American Physical Society